The present invention relates to dishwashers and in particular to dishwashers providing forced air flow during the drying cycle.
Dishwashers, such as those used in a home, may provide for a washing cycle followed by a drying cycle, the latter intended to dry the washed dishes sufficiently so that they may be immediately removed from the dishwasher and stored without additional manual drying. In many cases, the drying cycle includes activation of a heating element exposed at the bottom of the washing volume to heat the dishes and create an upward convective flow of hot air.
Improved drying of the dishes during the drying cycle can be obtained by venting the washing volume using vents typically located at the bottom edge of the dishwasher door and through the door near the top of the door. The vents allow cooler dry air to enter the dishwasher volume at the bottom of the door, drawn by the convective air flow, and heated moist air to be discharged through the door near its top.
One drawback to vents is that they can increase the noise emitted from the dishwasher during the washing cycle and accordingly, it is known to provide for vents having an electrically actuable door that may block the vents during the washing cycle thereby cutting emitted noise. One vent of this type is described in U.S. Pat. No. 6,293,289 entitled: “Surge Pressure Vent For Low Noise Dishwasher”. Venting can also be obtained by partially opening the door at the conclusion of the washing cycle as disclosed in U.S. Patent Application US 2004/0163684 entitled: “Automatic Door For Dishwasher”. Both of these patents are assigned to the assignee of the present invention and hereby incorporated by reference.
Venting systems can be improved by the addition of a blower to increase the passage of air through the washing volume. Generally such blowers are arranged to reinforce the natural convective flow of air thereby obtaining the benefit from the blower and the convection action of the heater used during the drying cycle.